


Bring Me Back A Dog

by DadIWriteGayPorn



Category: Harry Potter - Fandom, Harry Potter - J. K. Rowling
Genre: Age Difference, Anal Fingering, Anal Sex, Animagus Bestiality, Bedroom Sex, Birthday Sex, Consensual Underage Sex, Dom Harry Potter, Dom Sirius Black, Gay Sex, Knotting, M/M, Multi, Oral Knotting, Sub Harry Potter, Sub Sirius Black, Watersports
Language: English
Status: Completed
Published: 2019-04-15
Updated: 2019-11-14
Packaged: 2020-01-14 16:14:27
Rating: Explicit
Warnings: Underage
Chapters: 4
Words: 16,109
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18479788
Author URL: https://archiveofourown.org/users/DadIWriteGayPorn/pseuds/DadIWriteGayPorn
Summary: Harry has been begging his Godfather, Sirius, to lie with him as Padfoot for weeks. On his birthday he finally gets his wish





	1. Give A Little Love, Bring Me Back A Dog

**Author's Note:**

> I now have a tumblr where I post updates and answer questions and post random fandom stuff: https://www.tumblr.com/blog/dad-i-write-gay-porn

**Notes for the Chapter:**

> I've written human on human, and I've written canine on canine. Figured it was about time I combined the two. Also, I was really horny at 3AM and the idea hit me out of nowhere (well, less an idea, more of a "say, now that's hot"), and thus the writing began. This'll most likely be a one-off with no follow up. Simply because there's only really one place the "story" can go  
> From here, and I'd rather not repeat all this just to get to that. But I digress. Hope you pervs enjoy this. I know I did!

Harry had been asking Sirius for it for weeks. Ever since he had arrived at Grimmauld Place for the summer holidays. He'd been timid at first, asking his Godfather the first night back before they fell asleep, both naked and with Sirius' dick in his ass. 

"Erm, Sirius?" The boy cleared his throat, hole clenching slightly. Sirius had opened one eye curiously. Even in the darkness of their room he could tell the younger boy was blushing. 

"Hmm?" Sirius had asked, closing the eye back. 

Harry gnawed on his bottom lip, clearly working up the courage to say what he wanted to say. Finally, it spilled out of him. "Well. . . I was wondering. . . Since we've been having sex for a while now. . . D'you think. . . Would it be possible to have Padfoot fuck me?"

Sirius' eyes had flashed open at that. The man suddenly felt wide awake. He sat up, hand on Harry's hip, staring in disbelief at his Godson. "Wha-?! No!" The rejection came tumbling out of his mouth before he gave the request any thought. Sirius blushed. "I mean, not yet, Harry." 

Sirius' denial wasn't even due to the taboo nature of Harry's request. In fact, the more he thought about it the more the older man liked the idea of transforming into his bear-like dog self and fucking Harry. But he held himself back. _I've never fucked anyone or anything as a dog! I've never even had an orgasm, or even a boner as one! I don't want to accidentally hurt him. . . ._

But Harry was persistent. Every few days he would ask again. And Sirius would always give the same answer: not yet. And every time Harry asked, more of Sirius' resolve would be chipped away, allowing his desire to fulfill his Godson's wish to grow. 

But he'd managed to hold off until tonight. The big night. July 31st. It was Harry's 15th birthday! Sirius had cooked dinner, and they'd had some of the birthday cake the Weasleys had sent Harry by owl post for dessert. All the while Sirius was only thinking about how when they went up to bed he would finally give Harry what the boy had been begging for. 

He was both surprised and relieved that Harry hadn't asked him all day to fuck him in his dog form. His birthday would've been the perfect way to try and edge Sirius down the path of total moral dissonance. And Sirius knew that, had Harry asked him, they wouldn't have made it to bedtime. He would've vanished their clothes and transformed then and there, then taken the boy like a bitch. 

But they'd made it! Both of them. Sirius was naked under the covers, as he always was at night, when Harry came into the master bedroom from brushing his teeth. He was wearing plain black pajamas. Sirius tssked as Harry closed and locked the bedroom door behind him. 

"Harry, how many times do I have to tell you? You don't need any clothes for bedtime. Even on nights when we're not having sex." 

Harry blushed. "Sorry, Sirius! I just like wearing them in the house. I don't like the portraits or Kreacher watching me." He started to tug off his pajama shirt as he walked towards the bed. 

"No portraits in here," Sirius chuckled, watching the boy undress. Harry had slim, smooth features. The product of being underfed by the Dursleys most of his life, then becoming an athlete at school. He'd developed muscles but no body mass. 

"You said I should be naked even when we're not having sex," Harry said as he tossed aside the shirt and started on his bottoms. Sirius licked his lips as he took in the sight of Harry's nipples and pronounced hipbones. "Does that mean we're not having sex tonight?"

There was a slight dip of disappointment in the boy's voice. His pajama bottoms fell away, leaving him completely naked and with a semi; Harry loved to be watched, even by just Sirius. It was a thrill for him to have someone see him naked. Sirius stared as Harry stepped out of the pajamas and continued up into the bed, sliding under the covers with his Godfather. He had a lovely cock! It was a decent size for a boy his age; six inches when fully erect. There was just a hint of a black bush over top, and the boy's smooth foreskin completely covered his head. Of course, Harry's ass was just as succulent. Round and full and firm, with a perpetually tight rosebud. A Seeker's ass. His father's ass. 

Sirius realized he hadn't yet responded to Harry. The teen had climbed under the covers & edged close to him, and was now staring at him, awaiting a response. 

"What kind of a question is that, Harry?" Sirius smiled kindly, reaching over to cup Harry's face in his hands. "It's your birthday, of course we're having sex!" He pulled the boy forward for a kiss. Their lips met, Sirius' hot and manly, and Harry's soft and tasting of his spearmint toothpaste. Harry let out a soft breath of relief and longing. 

Sirius pulled away. "But I haven't gotten you a proper birthday present yet!"

Harry blushed. "You don't have to. Honest! You're still a wanted fugitive, so it's not like you can go out and get me anything. Besides, you gave me my Firebolt third year!"

Sirius smiled again. "You're too kind, Harry. I still feel like I should give you something, though. It's true, I can't go out as _myself_ to get you anything. But I'm confident that, if I were to transform, I would be able to give you what you deserve." The older man's eyes twinkled. His hand sneaked up to Harry's bare thigh.

Harry's eyes widened as the full understanding of what Sirius meant hit him. He blushed a deep, deep red. "Y-you mean t-tonight's the night?!" He stammered, heart hammering in his chest, pumping more blood to his crotch at the mere thought of what was about to happen. 

Sirius nodded slowly, holding eye contact with his best friend's son. "I do, Harry. I must admit, I've been seriously looking forward to this, though evidently not half as much as you." He smiled wider, and his hand slid up further to wrap gently around Harry's boyhood. The young teen sighed, eyes fluttering lightly at the touch. 

"Are you. . ." Sirius chose his words carefully, "Are you _familiar_ with canine anatomy?" He started stroking Harry slowly beneath the covers, eyes never leaving the boy's face. 

Harry moaned softly and nodded. "Aahhh~ y-yeah. . . I had an aunt who bred dogs. . ." His voice turned briefly bitter, but as Sirius tightened his grip Harry returned to happiness. 

"So you know, then, that I may not fit? Not _all_ of me, anyway." 

Harry bit his lip as he tilted his head back, stretching his body and allowing Sirius a better angle to stroke him off. The teen nodded again. "I know. . . But I still want you to try! And. . . We don't have to start with my h-hole. . ." He trailed off, but his meaning was clear. _Harry, you naughty boy!_ Sirius found he was more proud and excited than surprised. The man nodded his head in acknowledgment. 

"When shall we start, eh? Should I finish you off with my hand first, or-?" 

"No!" Harry shook his head. "I m-mean, this feels wonderful and all, you touching me there, but I've waited so long already. And I wanna still be in the mood while we do it. Me and P-Padfoot." 

Sirius cracked a grin and released his hold on Harry's cock. "You'll want to lay down on your back in the center of the bed to start," he said while pulling away the bedcovers and tossing them in a heap on the floor, exposing them both. 

Sirius was much bigger than Harry. He had a good three to three-and-a-half inches on the boy. And his fit, muscular frame was covered in black and dark brown hair, making for a lovely contrast with Harry's mostly hairless body. Both men had large wrappers, though. Sirius' foreskin was so large his cock head barely peeked out. Harry's gave a bit more room, however. Still, in a minute neither of them would have need for their foreskin.

Harry did as his Godfather suggested and began to move to the center of the bed, grabbing his pillow and situating it between headboard and foot. He laid slowly on his back, and Sirius caught a quick glimpse at the boy's asshole. He felt a fresh wave of horniness roll over him. He had both seen and been inside of Harry's hole a multitude of times since they had first met at the end of Harry's third year, but each time was a thrill of its own. Besides, he'd never before been down in it the way he was about to be. 

Harry's head pressed into the pillow. He was forced to keep his knees up, else his feet push against the headboard. Sirius didn't mind. It was a gorgeous view, and nothing would spoil that. He began to crawl on top of the boy, squeezing between his legs. Harry's breath grew shallow as he stared up into the handsome face of his Godfather above him, those dark eyes, long hair, whippish smile, and well-formed features. 

Sirius pressed down and kissed the boy. Their lips met and their cocks began to rub together, trading pre. Harry reached up to grasp Sirius' face in his hands, moaning as they kissed. He could feel the older man's tongue seeking entry into his mouth and opened willingly for him. Their tongues met and wrapped around each other. 

They made out, man and boy, for only a minute before Sirius pulled back, concern on his face. "Harry," he murmured, "you should know. . . I've never done this before. Not in my other form." 

"I know," the scar-faced boy said, smiling reassuringly. "It's okay." 

"It's just. . . My animal impulses might take over. I might do. . . _things_ "

Harry nodded reassuringly. "It's alright, Sirius." 

The older man shook his head. "I just wanna make sure you know what you're getting into, what might happen. I don't want to hurt you, Harry." 

"Hey!" Harry raised his voice and gripped his Godfather's face tightly, feeling his whiskers under his fingers. "It's okay! Really! Whatever you do, I can take it. I _want_ to take it. I love you." 

Sirius took a deep breath, then chuckled and nodded. "Being silly," he muttered, more to himself than to his lover. He leaned down again to place one last kiss against the boy's lips. "Are you ready, then?" 

Harry nodded quickly. 

"And we're going for oral to start with?"

He nodded again. "I wanna taste you first. I wonder if you taste different as Padfoot." 

Sirius gulped. _God, he's so horny! I hope I make him happy!_

"Alright, then! There's nothing left to do. I love you. Happy fifteenth birthday, Harry!" 

Sirius closed his eyes, then began to _change!_ It started with the hair. All over his body it thickened and grew out. His knees bent backwards, his nose and mouth extended into Harry's face, becoming a muzzle and a snout. Sirius' hands morphed into massive paws, and a tail sprouted from his rear, wagging immediately. In only a few seconds Sirius had gone from man to dog. He was no longer Sirius. He was Padfoot. 

Padfoot wasted no time. He shifted forward, bringing his crotch up to Harry's face and angling his bottom half downward. Harry's breath caught fast in his throat as he laid eyes for the first time on Padfoot's cock. He'd seen the dog's sheath and balls plenty of times (though not up close like this; those times had only been stolen glances). But this was a league of its own!

Padfoot's dick was massive! Bigger even than Sirius' had been. Harry was still fairly certain he could fit it, but _damn!_ it had to be ten, eleven inches long, not counting the knot. The entire thing was an organic red color and shaped like a rocket, though there was a cylindrical tip protruding from the head. Veins could be seen completely covering the member, all white and purple, spiderwebbing out across it all. Every bit of the surface of Padfoot's cock was wet and slick, and pre was leaking out of the head at a rate which dwarfed any human. It had already started dripping down onto Harry's chin! He could feel the hotness of it on his flesh and very nearly growled with approval.

And the knot! The knot at the base of Padfoot's dick was something to behold indeed! Technically, it was _knots,_ Plural. Three of them. One on the top and two down the sides, forming a triangular shape. These bulbs combined were fatter and rounder than Harry's fist! If Padfoot was able to force them inside Harry, it wouldn't be without its fair share of pain, and it would certainly become stuck inside the boy until Sirius turned back into himself.

Still, while it looked daunting and very difficult, Harry wanted to try. He could tell already that, once inside, the knot's pleasure would negate all the pain it caused getting there. But he was getting ahead of himself. There was still much to do before it got to that possibility. It was doubtful that he would even be able to take the knot yet, regardless of pain. He wasn't stretched enough. 

Padfoot had stayed still the entire time Harry admired him. He knew what a big moment this was and didn't want to rush the boy. But his nose had begun twitching and he pawed at the bedding just over Harry's head. He was growing impatient. Harry grinned and reached a hand up to placate the dog. He wasn't ready to suck him off yet, still familiarizing himself with his new toy, but at the very least he could begin getting Padfoot off while he examined the canine member in his face. 

Harry wrapped a hand softly around the slick shaft. Despite the wetness, his grip was solid, not sliding an inch unless he wanted it to. Padfoot began panting lazily, clearly loving the feel. His cock dripped more pre down onto Harry, this time spilling onto the boy's Adam's Apple. 

Now that the initial introduction between Harry and this red rocket had been made, the boy's other senses began kicking in. The cock in his hand felt _wrong,_ but in all the right ways. It was hot to the touch, smooth, & sticky, and Harry could almost feel the blood pumping beneath the organ's slimy flesh. And he could smell the hormones and pheromones coming off Padfoot's cock. It reeked of sex, yet it was an ever so slightly different scent than what Harry was used to smelling when he and Sirius fucked. This was more primal and bestial. More down and dirty. As he breathed it in the boy felt something inside of his chest open its eyes and purr. He was ready. He wanted it. 

"Ok. . . Harry muttered, shifting his grip on Padfoot's dick and angling it towards his mouth. "Here goes. . . !"

The boy sat up as best he could. He raised his head a few inches off his pillow, opened his mouth, and began to slide the tip of the canine's cock inside. Immediately Padfoot's muscles clenched. His ears twitched and a high pleasurable whine escaped his throat. Harry couldn't agree more. The slick warmth of the cock felt both unrecognizable and at home against his lips, inside his mouth. It actually felt almost like Chapstick or cream against his mouth, only it was warmer, stickier, and the taste was much different. 

It definitely tasted like a cock, just not any cock Harry had tasted before. The pre tasted like a stronger, older version of Sirius' own precum. And there was a lot of it! Harry found that every few seconds he would have to swallow it down. It wasn't necessarily coming out quickly and filling his mouth, but with that big a cock in his maw there wasn't a lot of room left for the pre that was spilling out. 

And that was another issue. The sheer size of Padfoot's cock! It was hard for Harry to keep his teeth away from Padfoot's extremely sensitive shaft. He was used to sucking Sirius off, using his tongue to exploit his head under his foreskin. That combined with bobbing his head usually made Sirius cum after only a few minutes. But this was something else entirely. Padfoot was so much bigger that, once Harry opened his jaw enough to keep his teeth away from the canine shaft, his tongue had no mobility. And with the position the boy was in, he wouldn't be able to bob his head very much. 

Harry supposed he could ask Padfoot to simply lie down and raise a leg, almost as if he was marking territory. That would make blowing him much easier, and Harry would be able to bob his head more. But he liked having the dog on top of him. It felt more domineering and passive that way, playing into the boy's submissiveness. Still, there were other things Harry could do to make Padfoot cum in his mouth. 

Harry shifted his grip so that it was around Padfoot's knot and started squeezing softly. The dog's whining and whimpering raised in volume and intensity. His pants became deeper and more labored. Harry smirked. It was working! He pulled his head back, letting his lips roll over the dog's head while his tongue teased at its protruding cylindrical tidbit. 

Suddenly, Padfoot started to thrust slowly into Harry's mouth. He felt the shaft slide against his tongue, pushing towards his throat. Harry moaned. That was one problem solved! 

He could tell that Padfoot was being careful. As much as he wanted to embrace his animal impulses and fuck Harry's throat hard and raw, he was keeping his patience. His muscles were tightly clenched, a clear sign of deliberation. Still, it wouldn't be long before he shot his load. Dogs didn't take long, and Harry could hear Padfoot's stamina waning with each squeeze of his bulb. The boy tightened his grip. 

_I can't believe this is actually happening! I'm sucking off a dog! A real dog! He may be my Godfather, but that's a real knot in my hand, a real red rocket I'm tasting!_

Harry moaned again, and Padfoot let out a low howl. He was getting close. Harry could feel it. He squeezed harder, urging the dog to cum. He wanted to taste him! He wanted his throat to become coated in canine semen. 

And he didn't have to wait much longer. Only a minute later Padfoot gave a shaky _"Ar-arrf!"_ and his large cock started to twitch. Knowing that Harry wanted to taste him, Padfoot pulled back so that only the head of his dick remained inside the boy's mouth. The member throbbed and twitched hard, threatening to pull free of Harry's lips. One of Padfoot's rear legs started twitching and kicking out, then the hot cum exploded forth, filling the teen's mouth. 

It was a bigger load than Sirius had ever given him. It flowed forth like water from a bottle, only thick and rich. The taste was drastically different than what Harry was used to. It was still identifiable as semen, but as with so much of Harry's Godfather in this form, it wasn't like any he'd had before! Perhaps it was simply because the flavor was so different from what Harry was used to, but he could've sworn it tasted stronger than human semen! It was simultaneously bitter and delicious, and the wrongness of the taste made Harry lightheaded and made his gut tighten with lust. He swallowed it down as fast as he was able and imagined that he could feel the hotness of it churn inside his stomach. 

Padfoot slowly pulled his still dripping cock the rest of the way out and gave a single bark, as though to say "how was that?" 

Harry shivered slightly from nerves and wiped his mouth on his shoulder as the last bit of Padfoot's cum dripped from the canine's penis onto his chest and the base of his neck. "Th-that was _incredible!_ Thank you so much!" The boy reached up and rubbed the dog's furred sides. Padfoot closed his eyes lazily. "Shall we move on to the real sex now?" Harry asked, still tasting the dog on his tongue and feeling its seed in his throat. 

Padfoot whined and barked again, then began to climb clumsily off the teenager. Harry knew exactly what to do. He threw his pillow back up by the headboard, then clambered after it, sinking onto his hands and knees. The bear-like black dog came up behind him, sniffing his asshole and tickling Harry with his whiskers. Harry giggled, clenching slightly. 

And then Padfoot's tongue slipped out against Harry's hole. The teen took a sharp breath. It was rough, but wet. He got the feeling that Padfoot was only doing this to tease and taste him. Unlike usual, it would take too much licking to get inside him while Sirius was in dog form. Canine tongues didn't have the same mobility as human ones. Harry appreciated it all the same. 

Padfoot continued licking for a couple of minutes, tongue running from the smooth back of Harry's ballsack, up through his valley and over his asshole. Harry gasped and moaned with each lick, eyes closing slowly. He was only just falling into the rhythm of the licks when Padfoot suddenly stopped, pulling back. Harry almost wanted to complain, but he knew what this meant and kept quiet. 

And sure enough, the next thing he knew Harry was being mounted! Padfoot leapt up onto his back, throwing his front paws over the teen's shoulders. Harry felt the warm softness of the furred body press against him. Perhaps it was due to the nature of being an Animagus, but Padfoot didn't smell like a dog. Not in the traditional sense, anyway. He smelled clean, like soap, but also uniquely animalistic, like pine and fresh water. Harry couldn't get enough of the scent. 

He felt it as Padfoot brought his hips up and pressed his cock testingly against Harry's hole. Only, he couldn't quite make contact. Not dead-on, anyway. It kept slipping down, or pressing too high up before sliding onto Harry's back. Padfoot let out a whimper and Harry understood immediately. He reached a shaking hand back with some difficulty and grabbed blindly for the large canine cock. His hand wrapped sloppily around it, and Harry helped the dog position itself against his hole. He held the dick in place. 

Padfoot's tongue really hadn't done much to lubricate or loosen Harry's asshole. It truly had been an exercise simply for the two males' enjoyment. But Padfoot's cock, specifically its profusely leaked precum, _did_ help lube Harry up! It seeped freely out of the tube-like protrusion at Padfoot's head and dripped down onto Harry and the bedding. They both hoped it would be enough. Harry helped his Dogfather wipe the cock head against his hole, slickening it up as best they could. And finally he was as ready as he would ever be. Harry slid his hand as far up Padfoot's dick as he could reach at that angle. 

"Ok, Sirius. . . I'm ready. If it looks like I'm in pain at first, I want you to keep going. It'll pass. I want this!" 

Padfoot seemed to hesitate, but with a squeeze from Harry, he yipped out and drove his cock forward inside the boy. The lube did its job and bypassed most of the pain, but Harry was still slammed by a large amount before any other sensation reached him. He cried out, vision turning red before he squeezed his eyes shut and grit his teeth. Padfoot continued to press inside the boy even as Harry's hand fell limply away. The dog did not stop until its cock was inside Harry down to just before the knot. Padfoot stilled, letting the boy get used to the feel of the member inside him. 

Harry was no stranger to dicks. He took Sirius' on the regular during the holidays when he was back at Grimmauld Place, away from Hogwarts. Trouble was, he was away at school for such long periods of time that the first night back was always a stretch for him. Much like his hair growing back when anyone tried to cut it, Harry's asshole seemed to tighten back up over the time he was away from his Godfather. This meant that the first time after school always held some pain for him. In fact, if he and Sirius waited just a week between anal penetration Harry's hole would grow tight again, and then would come the pain. He could usually take it. 

But this was something else entirely. In this form Sirius was bigger, both in length and in width. It didn't matter that Harry was still loosened from earlier that week, or that his hole was somewhat lubricated. His opening had never been stretched that wide. Pain was flashing through his body in shocks. His face was aflame, his jaw clenched shut as he hissed. Padfoot whined apologetically and licked the teen's cheek. It was lucky that his cock thinned out a little above his knot. This helped Harry grow used to the feelings faster. What was more, Padfoot's cock being firmly inside the boy, even unmoving, made Harry's natural lubricants start flowing, adding to the precum that was already there. 

The pain, as Harry had known it would, had started to fade quickly. It went from a searing sharpness to a dull ache in the space of just over a minute. He opened his eyes, panting fast. His arms and legs were shaking. He brought up the hand he'd used to guide Padfoot inside of him and used it to help support himself. 

"It's. . . It's going away," he gasped. "Wait another minute, then start thrusting. . . Slowly." 

Padfoot gave Harry another lick to tell the boy he understood, but Harry felt his cock twitch impatiently inside him, eliciting a quiet gasp. Harry recalled what Sirius had told him just before transforming. _My animal impulses might take over._

Now that the pain was fading, Harry almost hoped they would. Sirius was good at making love, but he was always overly careful. Some nights Harry wanted to be fucked into the dirt, to become one with it. Filthy and lowly. But Sirius, even after hearing Harry beg for it, went too easy. He was afraid to hurt the boy, so much so that he never came close, no matter if Harry wanted him to or not. It wasn't a fault, but it did become difficult not to feel a little bit disappointed. _Maybe tonight's the night?_

Padfoot, tired of waiting, began moving. Harry gasped as he felt the dog's dick sliding out of him. At first he moved slowly, deliberately. But it became readily apparent that his canine physique simply wasn't built for this sort of slow movement. Padfoot growled and thrust hard back into Harry, his knot and own hanging ballsack slapping into the boy. 

Harry, who had been hoping for but not expecting this kind of roughness, moaned out in deep appreciation. Already Padfoot was pulling back out and slamming back in, hitting right against Harry's sweet spot. This sent pleasure rolling through Harry. It wasn't the kind of pleasure that came with an orgasm (though it certainly led there if given enough time), but rather an intense pressing, aching pleasure. The boy's head fluttered as he moaned again, louder this time. Padfoot seemed to be moaning too. In this form it sounded more like a low cry in the back of his throat, but Harry could tell the dog was pleased. 

Padfoot started thrusting harder, exactly what Harry was hoping for. His pants and moans grew louder still, turning into cries and shouts of pleasure. 

"Aaahh! Aahhhh! Aahhhhahaha! Ohhhh yeaaahhh! Oh, yes! G-good boy!" 

Harry blushed, his head fuzzy. He knew Padfoot wasn't an actual dog. Not consciously anyway. It was still his Godfather in there. But he couldn't help speaking to him like a dog. It felt right and made his stomach burn with degradation. 

Padfoot didn't seem to mind. He just kept thrusting, going down to the knot each time. His tongue fell out lazily and he panted hard in Harry's ear. These sounds would've turned the teen on even more, but he was growing too preoccupied with the burning, twisting, stretching pleasure in his ass. On top of that, his arms were aching and shaking, threatening to give out. Between those two sensations, he could pay no mind to the sounds that both he and Padfoot were making. 

And the sounds escaping Harry's lips were growing more pitiful and pathetic by the minute. Every time the dog thrust into him his cock would strike true against Harry's prostate, which flooded his senses with pleasure. His vision was blurring with tears and because Harry couldn't concentrate enough to keep his eyes in focus. How could he? He was only 15 and being dominated by a dog. It was everything he wanted it to be~ 

But Padfoot's thrusts were going quicker and quicker, causing Harry to lurch backwards and forwards, threatening to spill his glasses off his face. In turn, the spaces between each of the dog's whines and every one of Harry's shouts were getting smaller. Harry was drooling onto his pillow, and the _slap slap slap slap slap_ of Padfoot's balls against Harry's ass joined the sounds of the two's moans and the _plap plap plap_ of the cock disappearing inside Harry's wet hole. 

"Ohhhh fuck! I'm c-close!" Harry gasped, trying to keep his eyes open, a futile and useless attempt seeing as how sweat was beginning to drop down into them, and how his glasses were sliding down his nose, making his vision blurry. But again Harry was far too occupied with the other sensations flooding his body to care. He could already feel it in his gut, the churning undulating pressure that signaled his coming orgasm. It was only a question of time. 

Padfoot gave a single booming bark. Harry wasn't sure if it was to egg him on or show solidarity. _maybe both?_ He remembered how easy it had been to make his Godfather cum just by sucking him off. In this form, it seemed like he should be cumming again soon. 

But Harry beat him to it! Even as a human, being a teenage boy meant he had very little stamina. Apparently less than Padfoot. The pressure in his gut burst outwards, making his skin tingle with pleasure. His cock started throbbing & twitching, and a second later his cum was flowing forth, shooting down onto the bedding. Harry closed his eyes and howled along with Padfoot. During his orgasm every sensation tripled in potency. Every thrust by the dog atop him, every strike of its cock against his sweet spot sent waves of energy-sucking pleasure coursing through him. 

It was almost too much to take. The only thing that kept Harry's arms from giving out was the thought that Padfoot hadn't came yet. And Harry wanted to feel that, to know what it was to have a dog cum inside him! As it turned out, he didn't have to wait much longer. 

Padfoot's thrusts at this point had reached a fervent rate of frequency, becoming truly feral. Soon enough he was howling loudest of all. He slammed his cock in hard and held it there, his knot pressing deep into Harry's asshole but not penetrating; Harry was still too tight. A glazed look crossed the faces of both boy and dog as the hot semen shot forth, filling the prior's asshole. The cock inside Harry convulsed multiple times, shooting a thick stream of cum with each twitch. 

Harry couldn't truly feel Padfoot's load until the dog pulled out and the cum started leaking. It was hot and sticky and the consistency of a thick syrup (though Harry now knew it tasted even better). As Padfoot pulled out and withdrew his paws from over Harry's shoulders, climbing off, Harry finally allowed his arms to unlock and fall away. He crashed down against the soft bedding, eyes closing and chest heaving, glasses barely on. He was covered with sweat and dog fur.

Only, Padfoot wasn't done. He moved beside Harry, lifted his hind leg, and began marking the boy as his. Harry gasped out, a shiver and shudder running through his body in spite of the hot liquid pouring over him, and his eyes flashed back open. He watched as Padfoot relieved himself onto him, the golden stream leaving the dog's penis covering Harry's chest and abdomen. The smell reached Harry's nose, strong and unique. He would have retched had he not secretly loved this. His face flushed as the last of Padfoot's urine dribbled out onto the bed. 

A minute later the dog was transforming back into Harry's naked Godfather. He was already blushing with remorse as the hair vanished from his face. 

"Harry! Are you alright? Did I hurt you?!"

Harry smirked softly. "Only the way I wanted you to."

Sirius shook his head, staring at his Godson's piss-soaked lower half. "I'm so sorry. . . My urges took over, I could fight them! Here, I'll clean you up," Sirius made to reach over for his wand, which was lying on the bedside table. But Harry stopped him, lurching forward to grab his Godfather's shoulder. 

"No, don't!" 

Sirius stopped, turning to stare at him. Harry's blush deepened. "I mean. . . Not yet. Soon! Just. . . Let me enjoy it a little while first."

**Notes for the Chapter:**

> Thanks for reading! If you liked/loved/hated this fic, leave a comment! I know you're probably disappointed that I didn't have Padfoot knot Harry. When writing/reading a bestiality fic, that seems like the obvious course to take. The trouble is, I like adding detail. As a writer, I like keeping things as closely grounded in reality as possible. I like painting a clear picture of how things happen and why. And, trust me, for a teen boy's first time taking a dog cock there is no way he's getting knotted! Wouldn't matter if they were fucking in a swimming pool filled with lube, that knot isn't going in on the first try without tearing and bleeding. And as blood, scat, and rape are pretty much the only things I won't write. . .
> 
> Still, I really hope you guys enjoyed and got off on reading this fic. I've had an idea for another Harry Potter bestiality fic in mind for 3-4 years that I wouldn't mind trying out if this one is received well. So leave a comment and let me know your thoughts! 
> 
> Also, for fans of this pairing, I have a cute Drabble you may like: 
> 
> https://archiveofourown.org/works/16915617


	2. Nature of Inviting

**Notes for the Chapter:**

> Well, fuck. I said I wasn't gonna write another chapter, but a ton of you in the comments asked me for one, and a ton of you on Facebook asked me for one, and I even got an email from one of you (that's dedication. . . But don't anyone else do that)! I had to read through the first chapter recently anyway to make a few small changes (my first edits didn't catch everything. . . Also I wanted to masturbate), and that turned me on & onto the idea (proposition, really) of making a second chapter. But this really is it this time! There won't be a chapter three (ish. . . Stick around at the end to hear more on that front). So enjoy it while you can (it's just like the weather, so quit complaining brother! No one lives forever!)
> 
>  
> 
> That being said, I hope you pervs enjoy this chapter; I'm trying to do some different things to set this apart from chapter one. I hope it's at least half as good. With that welcoming note. . .

THE WATER POURED QUICKLY DOWN Harry's back and over his asshole. The boy gasped as he speared a finger inside himself, trying to ignore the heat from the shower water turning his skin an angry red. He closed his eyes and slid in a second finger, this time from the other hand, then started to tug. 

Harry had been working the last few days on stretching his asshole. Most boys' goals were to stay tight for their partners, but Harry had a different goal in mind. Besides, it wasn't like he would stay loose. 

It was difficult keeping his hole stretched. Harry's body had a way of magically retightening his rosebud, just like how his hair always grew back within the next couple of days after being cut. This meant that Harry had to work quickly, taking early showers and having lots of sex with Sirius to keep himself loose. He wasn't complaining, and neither was his Godfather, though Sirius didn't know about Harry stretching himself. He had noticed the boy was less tight than usual, but assumed that was because of Padfoot. He didn't pay it any mind; the sex was still incredible, and he knew Harry would tighten up again given time. 

Every night in the shower Harry would crank up the heat, reach both hands back, slip fingers inside his hole, and pull. He'd bend forward, letting the hot water roll over his gaping orifice, and slowly stretch himself wider and wider until the pain became too strong to take. He didn't bother to keep his gasps and moans down. He liked Sirius hearing him. In fact, he was certain the older man was listening to him right now from their bed. Harry let out a loud moan just for him, and pictured his Godfather masturbating to all the sounds he was making. Had the teen's penis not already been erect, the picture in his mind would have stiffened it up within seconds. 

Tonight had been night four of Harry stretching himself. He was ready. He wanted to take Padfoot's knot. He'd been thinking about it all week, since his birthday when Sirius had finally, after weeks of Harry begging him, transformed and taken the boy. 

It had been some of the best sex of Harry's life! Rough and bestial. Harry couldn't get the feel of fur off his skin, the taste of canine semen off his tongue, or the feel of a knot pressing against his hole off his mind. Oh, that knot! It had felt amazing in his hand, pushed against his lips, teasing at his arsehole. Of everything Harry reminisced about, that was his favorite. And Harry didn't want to get away from these lingering tastes and feelings. He wanted to go _further!_

In the four days since Padfoot had fucked Harry, Sirius hadn't transformed once to please the boy. Harry had ridden him multiple times, but always with Sirius as a human. Harry didn't mind. He wanted to make sure the second time Padfoot fucked him would include a knot, which he needed to be prepared for, and it wasn't like Sirius wasn't good in bed as himself.

The boy knew Sirius didn't have the will to turn him down when he asked for Padfoot now. He was impulsive enough as it was, and after Harry's birthday night how could he say no? But Sirius, ever the gentleman, refused to bring it up himself. It would happen on Harry's terms. 

The boy pulled more, slipping in another finger for each hand. This time he was able to pull his hole open several inches before the pain began to creep up! In fact, he was pulling so hard his fingers threatened to slip out entirely! He smirked, letting out one last little moan and sigh, then relinquished his hold, straightening up & turning the shower off. The boy worked quickly with a towel. 

Harry walked out of the bathroom he shared with Sirius into their bedroom, still somewhat wet and achingly hard. There were times when Harry and Sirius would shower together (and do things that could in no way make them cleaner), but again that was only whenever Harry offered, save of course for the exceedingly rare days in which Sirius became too pent up and invited himself in. Harry loved those days! Sirius tended to be both rougher and more tender then. On those days when Sirius was horny enough he would play with Harry's nipples and bite Harry's neck while he bred him, making Harry moan louder and cum faster. 

The older man was lying on top of the bed covers waiting for Harry, completely nude and cock standing at attention. He eyed Harry with a cheeky smile as the teen stalked closer. 

"I could hear you again tonight. Playing with yourself, I presume?" A black eyebrow raised. 

Harry snorted. "I have you for that~ I'd say preparing myself." He slunk closer, now almost upon the wide four-poster bed.

Sirius' eyebrow rose higher. His hand drifted down towards his cock. Harry followed the motion for a moment, but looked back into his Godfather's face when he spoke again. "Preparing yourself? For what?" His stormy grey eyes met Harry's startlingly green ones, and instead of wrapping around his own hard member Sirius' hand shot out to grab Harry by the wrist.

He pulled the boy, gleeful and giggling, across his lap, then tilted Harry's head up. Harry leaned forward, expecting a kiss, but Sirius held him in place, hands tightening on fifteen-year-old. Harry growled with arousal before answering the question. Sirius was rarely this forceful. 

"For Padfoot~ I've been stretching myself, making sure I can fit him this time," Harry smirked as Sirius' hand moved to his throat. The older man wasn't choking him, just holding him, but Harry enjoyed the tightness of his grip there nonetheless. 

Sirius breathed deeply. "so that's why you've been loose these last few days! And you want him again, eh? Now?" 

Harry nodded slowly. "This time I want all of him, no holding back." 

"I wonder," Sirius' right hand released Harry's wrist and trailed up to the boy's chest instead, "why you get so turned on by being fucked by a dog? Not even your father or Remus were into that enough to try it, and I'd call you a liar if you said neither of them had ever thought about it before." 

Harry's eyes gleamed. He shifted his weight and put both hands against his Godfather's chest, straddling him. Sirius' cock pressed lightly against the top of Harry's ass crack, pointing up his spine.

"You remember taking me, not even 14 yet, for the first time?" He rolled his hips, making Sirius moan softly, and leaned forward, forcing more pressure from Sirius' left hand against his throat. "I'd asked you about my dad, you, and Lupin. Took some digging, but finally you explained how sometimes you'd sneak off and fuck, just the three of you, and that it had been a good 15, 16 years since you'd had sex. Longer than I'd been alive at the time." 

Harry felt Sirius' right hand move down his chest and stomach to wrap softly around his stiff cock. He rolled his hips again, thrusting into Sirius' hand. "Then I told you I'd never even masturbated before, and you stripped me down and fucked me until we both came." 

Sirius gasped deeply with longing and gave a shaky nod. "Aahh, h-how could I forget?" 

Harry smirked and continued thrusting into his Godfather's hand. He looked into the man's gorgeous face, seeing his sharp masculine features, his long black hair and short scruffily beard, his gentle and playful smile. Harry leaned forward again, and this time Sirius didn't stop him. Their lips met and Harry felt a balloon of light pressure expand in his chest. He tasted Sirius' whiskey and campfire lips briefly, then pulled back. 

"Well, that was a bigger and earlier sexual awakening than most people get. And it gave me an appetite~" Harry licked his lips. Sirius seemed almost frozen in place, lips parted and hand around Harry's throat, though neither were currently being utilized. 

"Now, are you gonna knot me or what?" 

Sirius had no choice. His right hand released Harry's cock and snapped up to the boy's shoulder. Before Harry could do more than gasp Sirius was rolling, lifting the boy up and putting him down, back against the bed. Harry let out an _umnph!_ as the air was knocked out of him. Sirius tightened his grip on Harry's throat for the space of a few seconds, then relinquished his hold completely. 

The man placed his hands on either side of Harry's head, just above his shoulders. His legs spread on either side of the boy's body as well. And then he began to transform. All over Sirius' body his black hair changed into fur, thickening & covering all his skin. His jaw morphed and jutted out, lengthening into a snout. His arms and legs bent backward, and his hands & feet changed into paws. A tail began to grow, and his cock grew larger, slicker, and redder. Three large bulbs grew at the base of his shaft and a small tube protruded from the tip of his cockhead. Padfoot was back. 

The canine growled and placed its right front paw firmly in the center of Harry's chest, then pressed down to show its dominance. Harry gasped and whined as he felt the soft yet rough pads on the bottom of the paw, and even some of Padfoot's claws press into his skin. Harry felt his heart pounding in his chest. Padfoot slowly added more weight, making Harry's chest feel tight, then took the weight away and moved his paw back beside the boy's head. 

The dog bared its teeth and nuzzled under Harry's head, but it was more an instruction than a loving gesture. Harry got the message and rolled over, sticking his ass in the air. He felt his back press against the hot fur of Padfoot's belly and sighed happily, pounding heart starting to relax. 

As he had done last time, Harry reached back as best he could to grab and help position Padfoot's red rocket. It felt slick and sticky in his hand, bigger and hotter than he was used to. He gripped the knot tauntingly and squeezed, making Padfoot whimper & squirm with pleasure. The boy smirked, then leaned down to press his face into the pillow and helped guide his Godfather's dick against his asshole. It was still loose and slightly wet from his shower, and the tip of Padfoot's head pressed inside him. 

"Give it all to me this time," Harry said. "No holding back unless I use our safeword." 

"Rrrrufff!" Padfoot barked his agreement, tail wagging. In this position there came no mounting, no legs over Harry's shoulders like last time. This time he wasn't on hands and knees, he was only on his knees. 

"Alright," Harry said, voice shaking slightly. "Alright, I'm ready. Fuck me, boy!"

The words were barely out of his mouth before Padfoot rammed his cock deep inside Harry's asshole! Harry's hand was knocked out of the way and fell limply at his side while the dog drove his dick forward. Had Harry not just exhaled he would have let loose a roar of pleasure. Padfoot's penis filled him with ease, pushing straight against the teen's sweet spot and rolling on through his secondary entrance. Even after all the stretching, Harry's boyhole clung to the dog's shaft. 

This time Sirius didn't even pause to let Harry get situated and grow used to his dick. He began thrusting immediately, delivering quick and powerful pushes with his rear legs to propel himself hard into the boy. Harry had experienced this last time, but only towards the end when his own orgasm was about to occur. He had been somewhat distracted by this, and had missed the sheer intensity of what Padfoot was doing to him. 

But now he felt everything. The ache of pleasure within himself that always accompanied Sirius' cock inside his asshole had become a ferocious unrelenting pounding. Already Harry was crying out, though he was somewhat muffled by the pillow. It would take everything Harry had to keep himself from shooting his wad before the dog knotted him. But while focusing on keeping his orgasm at bay, some other things within the boy slipped by undetected. 

After only the first few thrusts Harry couldn't take it anymore. He lost control of his own body outside of where his focus lay. His cock, which was bouncing up and down with the force of Padfoot's fucking, began to release a stream of piss. 

Harry didn't even notice he was peeing at first. He was so wrapped up in all the other feelings in his body that he didn't recognize the feel of his release. But then his stiff cock bounced up, the stream splashed onto Harry's face, a little going into his open mouth. This jolted and alerted him to what was happening. He blushed deeply, feeling embarrassed. This had never happened before, not even at the times when Sirius was being 'rough.'

And yet, even embarrassed, Harry couldn't help but be turned on more by this. It was the kind of fierceness and loss of control he'd been wanting for ages! The taste wasn't that bad, either. It was strong, but Harry was so horny he didn't care. The wrongness of everything added to the rightness. He swallowed the piss down and felt it coat his throat & corrupt his breath. 

The smell wasn't nearly as powerful as Padfoot's had been, either. He let the rest of his piss flow freely, seeping into the bed and occasionally spraying onto his chest and face. 

Padfoot sniffed the air curiously, slowing his thrusts as the scent of Harry's urine reached his nostrils. He cocked his head to the side, a low curious growl building up in his throat. Harry sighed as the last of his piss dripped onto the bed and he was given a small break from his Godfather's rabid thrusting. His ass hurt, but it was a good pain. One that made his blood rush and his muscles clench with longing. The dog's lips peeled back in what was unmistakably a grin, then he resumed delivering his powerful thrusts. 

Harry could feel the dog's knot hitting against his loosened asshole with every surge and push of the cock inside him. It was almost teasing him, barely beginning to press inside his butthole before being pulled back away. He wanted that knot inside him! Badly. With what little strength and capability of motion Harry had in this position, he began to push back against Padfoot's cock. He knew he could take it. On top of his slackened anal ring, Harry had a mixture of his own natural lubricants and Padfoot's excessively leaked canine precum to ensure a slick, if tight, entry. 

Padfoot himself was growing eager and impatient for the knotting as well. In this canine form he had half the stamina of his human form, and was already on the razor's edge. He gripped Harry's smooth young body tightly with his legs and prepared to fully enter the boy, tail wagging like mad. 

Harry felt the tightening of Padfoot's body around him. "Ooohhh, p-please! Do it, P-Padfoot! I wanna feel it. I want you l-locked inside of me! I need it~"

At last Padfoot obliged him. He let out a deep howling whine and gripped Harry's body even tighter with his legs, then began pressing his cock forward. Harry felt the full length of it slide slimily into him, and the knot begin to press against his hole. And then his ass began to stretch. And stretch. And keep stretching. It was more than what Harry had done to himself in the shower. _I misjudged how big he is!_

But Harry kept the safeword swallowed down and let Padfoot's knot stretch him more and more. Time seemed to slow down. Though the whole thing only took a matter of seconds, each moment felt long and drawn out. At first Harry only felt a strange sense of discomfort accompanying Padfoot's knot, but then the pain kicked in. It wasn't a searing, tearing pain (thank God!), but rather a deep burning, stabbing pain. Just enough to make Harry scream. He bit down hard on the pillow, not wanting Sirius to hear and stop. He could push through the pain. He'd been bitten by a Basilisk, broken his arm then had all the bones in that arm removed and regrown overnight. Harry had fallen over fifty feet from a broom to the ground and gotten more cuts and scrapes than he could count. He was no stranger to pain. And so he pushed through it, waiting for the pleasure he knew would come. 

And then the knot popped in! It went just like that. There was a hard thrust, an audible sound like a suction cup being ripped from a pane of glass, and then the knot was in. Harry's eyes went wide and glassy, and he took in a deep breath. He'd expected it to keep stretching him slowly, then to slide in like the rest of Padfoot's cock. He'd anticipated a slow, arduous journey of centimeter by centimeter. He hadn't expected the pop. 

And then the wall of new feelings reached him. Well, they weren't new, per se, but rather old familiar feelings multiplied by several times in intensity! The pain quickly dwindled away, becoming all but gone. The knot swelled within Harry as Padfoot started to cum, but Harry barely noticed. He felt so _full_ inside! Like someone had his guts clenched in their fist! He almost instinctively tried to push the cock out of his ass with only his rectal muscles. But he was stopped fast then the tense pleasure kicked in. 

The knot was pressing hard on Harry's prostate, milking it. As it swelled and convulsed with Padfoot's orgasm it pushed more and more firmly into the sweet spot. Harry's back curled and popped. 

"Aaaawwwooooooooooo!" Cried Padfoot, and he began to thrust with what little shaft lay between his knot and sheath, riding out the waves of pleasure he was feeling and squeezing out every drop of cum he could muster into the teen. As the dog bucked its hips Harry's prostate was assaulted, pounded against. He let out a strangled cry and drooled onto the pillow. It was too much to take! Not just the sensations running through his body, the intensity of the knot inside him, or even the taboo nature of what he was doing with a dog. It was how he and Padfoot were locked together that tipped the scales for Harry. The knot bonded Harry with his Godfather in ways that not even regular sex could do. As Harry's orgasm arrived he felt a greater sense of completion than he had ever known. 

Padfoot continued whimpering and bucking his hips into Harry. The boy's cum rocketed forth, shooting long and far, some spilling onto his chin. 

"Hh-HAAAAAAHHHHHHH!" The teen wasn't even able to consider biting the pillow this time before his scream of pleasure erupted from his lungs. "Oooooohhh G-God, Padfoot!" 

His cum continued spurting forth, adding to the already soiled bed's filth. Harry's back curled even more and his muscles convulsed as wave after wave of ecstasy crashed into him. All of his other senses outside the knot in his ass and the explosively powerful orgasm the teen was having turned to static. Harry'd had prostate orgasms before thanks to his Godfather and his own fingers, but nothing like this! Even after Harry had expended and expunged all his cum the pleasure kept coming, due entirely to the dog bulb pressing hard into his prostate. 

But eventually the pleasure and elation of Harry's orgasm dwindled away, leaving him breathless and covered in sweat, urine, and semen. Padfoot's body suddenly felt hotter and more compressing on top of him. His knot was starting to feel alien and unwelcome. 

But long gone were the days in which Harry would feel ashamed after Sirius made him cum. Here and now he felt pleased and fulfilled, if also drained and dirty. He panted hard and closed his eyes, smiling as he tried to find his breath. 

"Th-that. . . That. . . _thank you!"_ The teen grinned hazily and clenched his hole around the canine's knot, feeling it jostle within himself. Padfoot barked once then licked the back of Harry's neck, making him giggle. 

"Haha, I love you too! Can. . . Can you pull the knot out, or do you need to transform?" Harry was starting to ache all over. The position he was in wasn't good for long stretches of time. Padfoot cocked his head, then tugged experimentally with his hips. 

Harry gasped deeply, holding back a cry as he felt the knot pull backwards, stretching his hole. But Harry instinctively clenched all his muscles, holding the bulb in place inside himself. Padfoot stopped pulling and nuzzled Harry softly. He got the message: Padfoot wasn't going to rip the knot out if it would cause Harry distress. 

"It's alright. . . I'm ready to rest anyway." 

Padfoot gave a nod, then slowly began to transform back into Sirius. Most of his fur thinned out and vanished. His snout shrank back and his legs and paws became arms and hands again. Harry felt a peculiar deflating feeling as Padfoot's cock shrank slightly, knots hiding backwards inside of him and disappearing entirely. Sirius' hair grew long again and tickled the back of Harry's neck. 

"Well now, that was something!" The older man smiled and withdrew his cock from Harry's asshole with ease. A flood of canine semen spilled and dripped out of Harry onto the bed, but neither he nor Sirius paid it any mind. Immediately the two of them collapsed down onto the bed, finally letting their sore muscles relax. Neither cared that they were lying in piss and cum. A quick spell would take care of that mess when they were ready. 

They were lying on their sides, Harry's back curled against Sirius' front in spooning position, his back nuzzled against the man's hairy chest, head tucked under his chin. Sirius moaned as his muscles relaxed. He trailed two fingers up Harry's thigh, feeling his smooth skin, then wrapped the arm all the way around him, hugging the boy close. 

"I'm glad you talked me into doing that," Sirius kissed behind Harry's ear. Harry smiled, eyes closed, as the man's whiskers tickled him. "That was _incredible!_ and you took me like a champ." 

Harry sighed contentedly and nodded. "Didn't really need to do any convincing," he teased, "you're such a bad boy yourself."

"Haha, yeah, I suppose you're right." 

"I can't believe we didn't wake up your mum, what with my screaming and your howling," Harry said, referring jokingly to the shrieking portrait of Sirius' mother hanging downstairs. 

"I'm surprised the Muggles in the other apartments around us didn't hear, even with all the concealment charms!" Sirius teased back. Harry chuckled and let out a yawn. Sirius watched the boy with a smile. He shifted slightly and the bed squished beneath him. "There's gotta be a way to do this where neither of us ends up pissing." 

"Guess we'll have to practice," Harry grinned. "But I kinda like it." 

"I know you do," Sirius snorted, feeling the skin on his arm sticking to Harry's chest where the boy had peed on himself. "That's why I'm giving you a few minutes to rest in it before I clean us up. Call it your last birthday present."

**Notes for the Chapter:**

> hope you guys are happy! Think I'm getting the hang of beast fics. Now, this really is the last chapter for this fic, but. . . I smell a prequel fic! If/when that happens I'll put the link here in these end notes. I'm also working on that other Harry potter bestiality fic I mentioned in the chapter 1 notes. It'd be out by now, but it's not a canine fic so I'm having to do research (which sucks when your current main place to access wifi is Starbucks). 
> 
> https://www.youtube.com/watch?v=c369jewNOfA


	3. I Wanna Be Your Dog

**Notes for the Chapter:**

> I keel saying "this is the last chapter, " then thinking of something else I wanna do here. So, in the words of Sirius Black, sex God (or should I say sex dog?), "alright, what the hell. Let's do this!"

_"Again?!"_ Sirius asked incredulously, trying and failing not to look at his naked Godson while Harry gave him wide puppy-dog eyes. "Really, you want to do it again?" 

"Well, yeah!" Harry smiled cutely. "It's really good! Plus, you're rougher when you're like that and I like it rough." 

The boy was sitting up on his knees in his and Sirius' bed, arms locked straight and hands folded into his lap, with his back curving forwards to make his smooth, bare chest jut out seductively. Sirius could see his round pink nipples standing at attention and knew the boy's fickle must be as well. Harry blinked slowly, almost hypnotically, behind his circular glasses, his green eyes shining with hope. 

Sirius chuckled tiredly and sat up a bit, letting the covers fall off his bare, hairy chest as he set the book he had been perusing on the bedside table. "That was _supposed_ to be a one-time thing, you know? For your birthday." 

Harry swayed a little side to side. "Yeahhh, I know... But I really really like it!"

Sirius sighed and shook his head. "I'm sorry, Harry, but not tonight. We can do it again, I promise you, but right now I just don't have the energy, even if it does turn me on seeing you like this. Naked. Begging. Pleading." 

Harry pouted instantly. "Pleeeaaaseee? C'mon, Sirius, you could let me do all the work!" Harry started to bounce up and down a bit excitedly. Evidently he had a lot more energy than Sirius did, young as the boy was. 

"It's tempting, Harry. But when I'm Padfoot I can't exactly lay down on my back and let you ride me like we do when I'm in this form."

"Then I won't ride you." 

Sirius blinked. "Cone again?" 

Harry tried hard not to reply with _'I'm trying.'_ "C'mon, I've only sucked you off when you were in dog form the once! And I loved it. Let's go again! All you have to do is lay there for me, on your side." 

Sirius considered for a moment. He couldn't really see a downside. Harry was asking him, not the other way around. And honestly, a blowjob would really hit the spot right before bed.

"Alright," he decided. "What the hell, let's do it!" 

Harry's face split into a beaming smile and he scrambled happily across the bed to where Sirius lat. He quickly tore away the bedcovers, exposing Sirius' naked, toned form. The man's cock was already stiff. _Perfect! As it should be!_ His, foreskin was peeling slowly back even as Harry watched. 

"What can I say?" Sirius muttered in an undertone, pulling Harry's attention to his bearded, handsome face. "I love you." 

Harry grinned, then leaned forward. Sirius shifted so that he was lying in his side and met Harry's lips halfway. They were warm and delicious and just the slightest bit wet. They were **perfect**! Harry moaned into the kiss and placed his left hand against his Godfather's cheek, feeling scraggly beard. With his right he softly grabbed Sirius' cock, feeling the weight and warmth of it. 

The boy began to stroke slowly, feeling soft skin move under his fingers, and the coarse pubic hair press into his hand on each downstroke. Sirius moaned appreciatively, slipping Harry the tongue in thanks. Harry closed his eyes and entwined his tongue with Sirius', enjoying the familiarity of it in his mouth. 

But then Sirius began to change, and things began to feel exponentially less familiar (though Harry hoped to change that). The lips against his pushed back and grew thinner as Sirius' face elongated into a muzzle. The hair on his body thickened and softened into fur. The tongue in Harry's mouth widened and thinned out before slipping back out of Harry's mouth. 

And his cock! It grew thicker in Harry's hand, slicker, and a little bit longer, too! Harry knew without having to open his eyes that it had turned a deep shade of red. He could already feel the excessive precum starting to trickle down the shaft. And under Harry's hand, where before there had been a thick bush of pubes, Harry felt a thick knot growing. 

He pulled out of the kiss and opened his eyes. A large black dog was lying where only a minute earlier there had been Sirius, his red rocket standing tall in Harry's hand. Though Padfoot's eyes were slightly closed and tired-looking, Harry saw his muzzle open in what was unmistakably a smile. The dog whined once and dipped its head. 

Harry smiled back, nodding. "Thank you, Padfoot," he said before he released the canine cock in his hand and used both hands to ease himself into a new position with his face right up in the dog's crotch. 

Padfoot barked once, then leaned down to lick the back of Harry's neck lovingly, making the teen giggle. "Haha I know, I know. I love you too." 

Harry breathed in his companion's scent. It was always different from how Sirius smelled. In his human form he generally smelled manly, like leather and Firewhisky. But when he was a dog he smelled like nature. Pine and petrichor and, sometimes, a little musk. Not doglike at all, but Harry adored it anyway. 

But Padfoot's crotch, however, was a different story entirely. This reeked of musk and hormones and pheromones. It smelled the way a sweaty ballsack does, only stronger. The smell wasn't an invitation, it was a directive. An order. 

Harry's asshole clenched longingly. It had been well over a week since he'd last had that canine shaft buried inside him. He'd even managed to take the knot, too! It was one if the best feelings there is. He would've loved to have taken it tonight. But Sirius had told him 'no,' and while he was like to be more amenable to the idea in his dog form, once Sirius was back in his usual human body he would likely never let Harry fuck with Padfoot again after such a breach of trust. And it wasn't as if there wasn't plenty for Harry to do anyway. 

He started by licking softly from base to tip, tongue rolling over the knot and cleaning up quite a bit of rather strong-tasting pre along the way. Padfoot whined fitfully and started to pant. Harry delivered more licks, rising steadily up the length of the dog's shaft each time until finally he wrapped his lips around the head. 

Padfoot sighed and closed his eyes as Harry's tongue began to work on his tip. He sucked down as much pre as he could while sliding his tongue over the cylindrical protrusion from the head. His tongue slipped teasingly inside the cockhole, making Padfoot whine even louder. 

The boy soon began to bob his head, wanting more to play with than just the tip. It had been a while since the first and last time Harry had sucked Padfoot off, but in that time he'd learned from the lesson and was more prepared for it now. 

It was the width, not the length, that Harry had to deal with the most. He'd been sucking Sirius off for so long that his gag reflex was nothing but a distant memory. And in all honesty, the width wasn't even that bad. Sure, Padfoot was thick, but Harry liked that. His trouble lay in what he could do with that thickness, though. He could either bob his head or use his tongue. He couldn't do both. 

But since last time he'd mostly used his tongue and hand to make Padfoot cum, he wanted to try something else now. Something thrilling! _I could fit it inside my ass, after all. Why not my mouth?_

Harry moaned a bit and began to bob his head deeper. His left hand grabbed the base of Padfoot's dick below the knot and held the whole member in place. It felt so hot and rightfully wrong in his grip, but even more so against his lips. 

He started to take more of the cock in each bob of his head, creeping it back towards his throat. And slowly but steadily it got there, sliding down past Harry's uvula. He could feel the slickness of the pre sticking to the walls of his throat as his lips started to part further, rolling up to Padfoot's knot. 

Padfoot groaned and whimpered. Harry ignored him and pulled his head back up, then delved back down. He worked slowly into a rhythm. It was a lot like when Harry would deepthroat Sirius, only a bit bigger, slicker, and (if he was being honest) more delicious. 

Under these circumstances Sirius would finish after only a few minutes. Padfoot had less stamina than Sirius did, so Harry was expecting him to cum fairly quickly. And while he was looking forward to his Godfather ejaculating down his throat, that wasn't the main end goal Harry had in mind. 

It was all about confidence. Confidence and courage. Harry knew what he wanted. He knew he could do it. He knew he would like it. He knew Sirius would like it, too. Maybe even more than Harry would. And he was already breathing through his nose alone anyway. But the boy had trouble gathering the courage and confidence necessary for what he planned on doing. 

He couldn't help but think, as he continued to deepthroat the dog, about how this would be his first attempt. What if he did it wrong? What if he accidentally grazed Padfoot with a tooth? 

_I can do this. I can do this!_ Harry began taking deep breaths through his nose. With his free hand he reached up and started to fondle Padfoot's balls. It was something that he'd started off doing to Sirius jokingly, but had evolved since then into something that actually calmed him these days. Padfoot's testicles were, unsurprisingly, just as effective as Sirius'. They hung down more, and were thus better for playing with, even if they were furry. 

Padfoot seemed to recognize the calming activity, and put two and two together, realizing what Harry planned. He quieted down, giving Harry his full attention and, evidently, permission. 

_I'm ready!_

Harry pulled up the length of Padfoot's shaft one last time, tugging it free from his throat. He stopped with just the tip still in his mouth, cradled by his tongue. Harry opened his mouth as wide as it would go, then drove himself forward. Padfoot whined loudly, unable to help himself as Harry's throat reclaimed his cock. But Harry kept going, past where he'd stopped before. The knot pressed against his lips again and slowly began to slide through them. Harry could feel it against his tongue! A large, hot, throbbing bulb. 

It ended up being easier than Harry thought it would be. With everything so slick it slid in with ease. It had looked so daunting before, but now with it halfway past his lips and nowhere to go but onward Harry would have laughed with relief and victory. Were there not a cock down his throat, of course. He clenched the hand he had around Padfoot's base and gulped, with difficulty. 

And then, without one scratch from Harry's teeth, Padfoot's knot popped all the way inside Harry's mouth. The dog howled out in both celebration and ecstasy. Harry's heart beat hard in his chest an his head swam with a desire to cheer, though he knew it would be quite impossible to do. He'd done it! For the second time ever Padfoot and his Godson were tied together, this time with the fat knot sandwiched between Harry's tongue and the roof of his mouth. The boy could feel sweat trickling down his forehead but ignored it. He only had the attention for Padfoot.

And it was getting to he too much for the dog. The now constant pressure. It was like someone were squeezing his knot, delivering perfect pleasure that could not be ignored. He groaned and panted and began to thrust his cock as best he could, trying to warn Harry and almost bringing back his gag reflex in the process. 

Padfoot only got two good thrusts in before it happened. Harry felt the entire member throb inside him. He took a deep breath, one he knew he would need, just as Padfoot gave a long, pitiful whine. A second later and he was cumming. Cumming hard, too. Right down Harry's throat. 

Harry did his best to swallow it all down, but Padfoot was cumming faster than he could gulp! Soon some of his doggy cum had overflowed into Harry's mouth, but unable to work with his tongue to keep it in there, what with the knot weighing it down, the stuff continued up and out his lips, dribbling down Harry's chin. 

 

It was a large orgasm, but not a long one. After only ten or so seconds Padfoot stopped whimpering and his cock ceased to throb and spit out its cum. Harry was able to gulp the rest of it down as the dog panted hard, catching its breath. 

And Harry was faced with a problem he hadn't anticipated. _How… how do I get it out of my mouth?!_ Getting it in had been relatively easy. But the boy quickly found that untying them was a different story. It was almost as though Padfoot's bulb had swelled even larger while inside Harry's mouth. No matter how wide he opened his jaw, the knot was still too big to pull past his teeth. And while Harry was still horny, having not came yet himself, this position was quickly becoming uncomfortable. 

Harry groaned softly, making eye contact with the beast in his mouth, trying to silently relay his problem. Padfoot met his gaze and appeared to nod in understanding. Harry waited a moment, trying his best to remain still. At first nothing happened. Padfoot remained as he was, with his tongue lolling out as he breathed quickly. 

But then he started to change again. Fur retracted into skin, paws became hands once more, his face shrank back in, becoming gradually more and more human, his eyes returned to their natural size and color, and the cock in Harry's mouth, down the back of his throat, started to shrink. The knot deflated quicker than Harry would have thought possible, until it was entirely gone in almost five seconds. The rest of Padfoot's anatomy followed the swap with Sirius' until it was his Godfather's dick down Harry's throat. 

The boy pulled off him quickly, gasping for air. He felt unbelievably hot, an was surprised that he wasn't soaked in sweat. There was some on his face and back, but for the most part he was dry. A rare thing for after sex with his Godfather. He almost always came out if it drenched, one way or another. 

"That was exactly what I needed, Harry," Sirius murmured tiredly a moment later when the boy had caught his breath. "Thank you."

He cupped Harry's face and pulled him close. Their lips met, gently this time. The kiss was soft and thankful, rather than fierce and passionate as they'd done earlier. And Sirius could taste Padfoot's seed on Harry's lips, in his mouth. He liked it. Soon he moved his mouth down to the right side of the boy's chin, licking up the last bit of canine cum that had spilled out of Harry's mouth. 

They collapsed down onto the bed, heads on pillows. Both felt exhausted now, but Harry still had a raging boner. One that Sirius eyed lazily through half-closed eyes. 

The man's hand found its way to Harry's cock, gripping it well and making the boy gasp out. 

"You're a dirty boy, Harry," Sirius muttered as he began to stroke him off. "First you're a boy who fucks his Godfather of twenty years your senior. But then you wanna fuck a dog?" He stroked faster. "Slutty boy~ _My_ slutty boy!" 

"Ahghh heehhnnm~" Harry rolled his hips and closed his eyes, skin tingling at Sirius' touch and words. 

"You've taken my knot, a dog knot, twice now! And you loved it, you naughty teen. You've had my piss and you've choked on me multiple times. What's next, baby?" Sirius' strokes became harder, and the _slap slap slap_ of flesh on flesh reached Harry's ears. 

"You've pulled me so far out of my comfort zone and taught me to enjoy every second of it. You've a filthier mind than I ever had, and that's really saying something." 

"S-S-SIRRRIIUUUUUUUSSSSS! Harry cried out, squirming in place and arching his back. "CCCXUUUUMMINNNGGGG!!!!!!!! AAAHHHHHHHAAHAHAHAH FUCK!" 

Sirius gave a final downstroke and Harry's seed rocketed up out of his cockslit. It arced through the air and came to land in a messy splatter on the boy's chest. 

"Goooddd boooyy~," Sirius crooned, waiting for the last drop to be projected out, leaving tiny trails of cum down to Harry's stomach. He released the teen's cock and edged closer to him, wrapping his arms around Harry and getting the cum on himself.

 

"I love you. You know that. I love you more than anything. You have a burning intensity, and I'm like a moth around it, Harry. I never wanna give you up." He kissed Harry's forehead. The boy sighed contentedly and kept his eyes closed, melting into his Godfather's embrace.

"You never will. I love you too, Sirius."


	4. I Wanna Feel You From The Inside

**Summary for the Chapter:**

> Harry gets a rare urge and fucks Padfoot

**Notes for the Chapter:**

> Damn me! Every time I think I'm done with this fic and start working on updates for other fics, I get caught up in this one again. This was supposed to be a oneshot and now look at it. Anyway, I'm fairly confident that this is indeed the final chapter. For real this time. It's the last way to switch things up without getting into territory I'm not comfortable with (which is saying a lot considering what this fic is) or adding new people. . . Fuck.

Harry whined out as he bucked his hips forward, neediness and carnality in every tiny movement. His fists clenched and his toes curled. He could feel everything and nothing all at once. He had no idea where he was, but that did not matter. 

It was so soft and warm and perfect here. The man he was rutting into felt hot to the touch. He could feel fluffy hair and sweat on the man's skin, accompanied by whines that were much akin to his own. It felt so fucking good! He wouldn't last. Harry only needed a few more thrusts! Just a little bit further and he would be-

_"Harry?!"_

Someone grabbed the teen's shoulders and shook him firmly awake. His eyes snapped open, but it took him a minute to figure out where he was. The room he was in was dark yet familiar. After an initial moment of confusion, the boy was able to make out his and Sirius' bed as well as his Godfather leaning over him. He could only just see the curious look on the man's scruffy, handsome face. 

"S-Sirius? Why'd you wake me up? I was having a good dream." 

"You were humping my leg, Harry," the older man explained softly. "And whining. It woke me up." 

Harry's face flushed. It had been _that_ kind of dream. 

"S-sorry, I didn't mean to." 

Harry heard Sirius whisper something and suddenly a low orange light flared to life at their bedside table. Harry squinted at the sudden light, but Sirius seemed unperturbed. He scarcely even blinked as the glow filled the room and sat up so some of his muscular, tattooed form showed over the covers. Sirius peered pensively down at the naked boy beside him. 

"Merlin, you're as stiff as can be!" the older man observed, looking down at Harry's crotch. It was true, the dream had given Harry an erection so hard that it actually felt sore! It was the kind of dull, aching, satisfied soreness you get from productivity, though Harry had been far from productive. He was leaking quite a lot of pre, however. Already there were dots of wetness in the white sheets from it. 

"We just fucked only a few hours ago, before bed," Sirius said, resting a hand gently on Harry's knee. "I hope I didn't leave you unsatisfied?" 

Harry shook his head quickly, eyes widening despite the light. "No! No, nothing like that. You were incredible, Sirius. Really. You're _always_ incredible. It's just. . . ." Harry felt a strange emotion more in his gut than in his heart well up. It was sexual in nature but not one Harry was particularly familiar with. The teen looked away, blushing even fiercer. 

"What?" Sirius cocked his head to the side, looking at Harry with a concerned, puzzled expression. "What is it, Harry? It's alright, you can tell me anything." 

"Well. . ." Harry licked his lips, trying to pull all the feelings he'd had during the dream back to the surface, to analyze them alongside the new emotions he was feeling. "I love being a sub. Honest! It's always wonderful, and it really suits me. But I've never... I've never put my cock in anything that wasn't my hand or your mouth. And I think, even though I prefer bottoming, I'm getting pent up. I need to fuck something!" 

Harry peered sheepishly up at his Godfather, hoping the man understood him. Sirius gave a single nod. 

"Ah, yes, that is a problem." 

Harry blushed again. "But is it okay?" 

"Don't worry, Harry. After all those times when I'd make love to you, I surely can return the favor. Besides, seeing you so needy like you were a moment ago in your sleep... I could never deny you that. The only issue is, well, I've never really bottomed before." Sirius ran a hand embarrassedly through his hair, inadvertently showing off flexing muscles that, under normal circumstances, would've had Harry presenting within a millisecond. 

Harry, more caught up in this new revelation as well as his own mixed feelings, blinked in surprise. Sirius seemed so in tune with his sexuality that Harry had been sure he'd bottomed at least once! Perhaps with Remus on a night closer to the full moon? It seemed only natural to a boy like Harry. 

"Really?! Not even fingers?" 

Sirius shook his head. "When your father, Remus, and I would get together at the Shrieking Shack Remus was exclusively on the bottom with your father in the middle. I'd always loved topping, and seemed to only attract bottoms anyway, so that's one cherry I haven't popped. And as for fingers, well, I've got quite a lot of hair back there, you see. And it's much more coarse than, say, my fur in my other form. I've never wanted or indeed had the will to shave, and when you're already tight back there even lube doesn't help much. Not when you don't want to do it in the first place, anyway." 

Harry's heart sank at those last few words. _He doesn't want to do it..._

His disappointment must have shown on his face because Sirius quickly backpedaled. 

"That's not to say I don't want to try it with you, Harry! Of course I do. Anything to help you get through this. I only meant it might be difficult." Sirius squeezed the boy's thigh reassuringly. 

Harry thought back to the last time Sirius had told him he would be willing to try something sexual he'd never done before. That had led to some of the best sex of both their lives. But this was different. With Padfoot they had both known it would work, they were just anxious about the taboo nature of it. But here there lay actual obstacles. 

An idea popped into Harry's head. A filthy, kinky, unbelievably taboo idea. There were probably other, more common ways around Sirius' obstacles, but now that Harry had thought of his idea he didn't want the other simple, _normal_ ways. 

"What if," Harry began in a slow tentative voice, "what if I fucked Padfoot? Softer fur, easier access, and you know how much I love to play with him!" 

Sirius swallowed, turning Quaffle red. Harry could tell by the shallow rise and fall of his bare chest that his breathing had become instantly restricted. But Harry also knew that Sirius loved fooling around with him as Padfoot almost every bit as much as Harry loved it himself. 

"That, ah," Sirius licked his lips and swallows again, "that could work! Are you sure you want to do that?" 

Harry nodded, sitting up eagerly. "Yeah, I am! Besides, I don't have to worry as much about accidentally hurting you when you're in your animal form. You fought a Werewolf in it and kept going. You like it rougher when you're Padfoot." The boy spoke matter-of-factly. 

Sirius nodded thoughtfully. "True, very true. Alright then, Harry. Let's give it a shot, for your sake. On one condition." 

"What's that?" Harry asked, sitting up more and unable to keep the excited grin off his face. Sirius sucked in a deep breath as the covers slid off the teen's smooth chest. Already he was feeling arousal. His member was rising and he could hear his heartbeat in his ear. 

"When you're done, I stay as I dog until morning. It's late and I don't have the focus to switch back. Especially after a breeding. Deal?" 

"Absolutely!" Harry couldn't believe that this was actually happening. He'd only ever bottomed before, and here he was about to fuck Sirius! _No, not Sirius. **Padfoot!** _

"You remember the prepping spells I use on you?" 

Harry nodded quickly. 

"Good. Then get your wand." 

Harry rolled eagerly out of their bed and made his way across the room to a dresser, atop which sat his own wand. As Harry made his way to retrieve it, Sirius transformed. Upon arriving back at the bed Harry was greeted with the large shaggy black dog that was Padfoot. His tail was wagging excitedly and he was already hard down below, as he'd been in his human form, and was leaking doggy pre onto the bedspread. _We'll have to clean these sheets tomorrow!_

As Harry climbed back onto the bed, cock swinging, Padfoot leaned in and licked a couple of good luck kisses across the teen's face. Harry giggled, wand in hand. 

Padfoot moved hurriedly into position in the middle of the bed. He stuck his rear up into the air and lowered his shaggy face down against the bedding, stretching his two front paws out before him. Harry gently stroked his furred sides and down his back as he circled around behind the large dog. 

He had to grab Padfoot's tail and lift it away to keep it from wagging across his backside. Once it was out of the way, however, Harry was treated with an inordinately sexy sight. A tight, clean hole sat exposed just under the tail where the fur was shorter. It was black just like the rest of Padfoot. And below that was his full hanging ballsack and sheath, protruding from which was his monster of a red cock, all its knots on display. 

Harry had to resist the urge to reach down and grasp Padfoot's red rocket. Beyond that, he had to hold himself back from crawling under the dog and presenting his own asshole. Padfoot wouldn't blink an eye. In his animal form he was much more agreeable, nay susceptible. But Harry had a job to do. He had to relieve himself, and his usual slutty ways wouldn't allow it. Just this once he needed to cum inside something the way his Godfather always, until now, came inside him! 

He placed the tip of his wand against Padfoot's rear entrance. _"Lubrico,"_ Harry muttered. His voice shook a little but he'd long since learned his lesson about mispronouncing spells. A slick (and warm, Harry knew) liquid squirted from the end, coating the outside of Padfoot's hole. The dog let out a soft sigh as Harry started pressing his wand tip into the now lubricated hole. 

It took a bit of pressure, but quickly enough the wand tip slid inside, making Padfoot give a single quick whine. 

_"Tergeo, Scourgify!"_ Harry rushed through this bit. These spells always made him feel strange both physically and internally, but it was a necessity. He wouldn't, _couldn't_ have it any other way. 

Done with this, Harry tugged his wand out and set it carefully aside. It was time for the proper fun to begin. 

The first finger slid in with relative ease. Padfoot's was softer than Harry's own asshole, though nearly equally as tight. He couldn't pull his eyes away from the sight of the middle finger disappearing squelchily inside the dog. He'd done a lot of wrong things with Padfoot in the past few months since his birthday, but this was at the top of the list. 

Harry's finger fit rather snugly inside the dog's hole. The inner walls gripped him welcomingly and the slick warmth of the lube invited him to proceed. Harry knew Padfoot was trying his hardest not to squirm. Though he was vastly more intelligent than real dogs, he still had hyper tendencies. Tendencies Harry wanted to exploit. 

He began to thrust his finger. 

Padfoot whined a little louder. Harry could feel muscles working uselessly in the tail he was holding. The dog's hole began to clench and unclench as Harry moved his middle finger back and forth. Whenever he pulled it out he could see his skin shining with lube. And the smell! Padfoot always smelled better than real dogs, but this was exquisitely tantalizing. Pure sex in the air. Musk and pre and pheromones. 

After a moment of thrusting Harry added a second finger, his pointer, though he was very unaccustomed to fingering anyone but himself and wasn't entirely sure Padfoot was ready. The canine took it like a champ, however. He whimpered more, but it was far from a whimper of pain or discomfort. Harry gave a self-satisfied smile as he thrust the two fingers down past the second knuckle. 

He didn't have much patience for a third finger, however. After only a few more thrusts Harry tugged both wet fingers out and eased forward to push himself against Padfoot's asshole. 

"Thanks for letting me do this," Harry said blushingly before popping both fingers into his mouth and sucking on them absent-mindedly for a moment. He could taste Padfoot's natural lubricants on them. The flavor was surprisingly similar to his cum, though not quite as strong.

The dog whimpered needily, its tail jerking in Harry's grasp and bringing the teen back into the present. He blushed and removed the fingers from his mouth, reaching instead to grip Padfoot's right haunch the way Sirius did to Harry's butt when they fucked. 

Before Padfoot could complain again, Harry thrust inside. He only went in a little bit at first. He wanted to experience everything properly for this first time, and he was tentative anyway due to his inexperience on this side of mating. 

He'd known it would feel good. He'd masturbated before, of course, and Sirius always loved fucking Harry. He wasn't an idiot, he knew that there was pleasure to be had from fucking as well as getting fucked. And maybe it was because he was always content receiving that he'd never really given _giving_ any thought. But he hadn't anticipated the full reality of it. 

He fit perfectly inside Padfoot's anus. It was snug and slick and hot. The lube doubled sensitivity in Harry's already hyperstimulated head, and every tiny movement sent shocks of pleasure through the teen's body, giving him goosebumps and making him breathe harder. Padfoot's fur surrounding his asshole was soft and cushioning, helping Harry as he started to thrust. 

Harry didn't wait or ease in slowly. After this first taste he was through with all that. He pushed all the way down, pulled all the way out, then back down balls deep again. Padfoot whined loudly but did not squirm at all. 

"Attaboy!" Harry panted, rubbing the dogs flank as a wet squelching sound began to fill the room. Harry's eyes grew heavily lidded as he worked his hips in a steady backwards and forwards motion, watching with disbelief and extreme pleasure as his shaft slid in and out of the canine anus. 

"Mmnnaaahhhh!!!" Harry was practically drooling. This was _exactly_ what he needed. Something to rut into, to breed. He picked up the pace a little, letting his balls tap lightly against the dog's at each downthrust. Sweat was already dripping down Harry's forehead just from this initial entry. 

He continued to increase the speed and power of his thrusts until he was pulling on Padfoot's tail to propel himself forward. The canine growled, but it was a playful, aroused growl free from any danger. Harry growled back, his ballsack now slapping into Padfoot's. They ached with each impact, but the sheer horniness Harry was feeling transmogrified those sensations into pleasant ones. 

There was only one problem. Harry was low on energy. They'd already fucked once that night, Harry could still feel the slightest sliver of soreness in his asshole to attest to that. And before then had been a long day. He'd only just woken up after precious few hours of sleep. Harry wasn't certain how long he could keep these thrusts up. Sleep was already calling to him again. 

_No!_ Harry scolded himself, yawning to keep himself awake. _You need this! You can't quit now, Harry! Just adjust._

He remembered the way Padfoot would fuck him, his body atop Harry's, front legs hanging off Harry's shoulders. The boy eased himself forward gently, dick sliding inside all the way, and released Padfoot's tail. He then draped himself over the dog, feeling hot, fluffy fur against his chest. Harry placed one hand down onto the bedding, arm rigid to hold him upright, and grasped at the fur down Padfoot's front with the other. 

At first Harry held himself up, afraid to put his full weight on top of the dog he was fucking. But as he slowly added more and more weight without Padfoot so much as shifting with discomfort Harry's worried eased. Soon he was lying properly atop the canine. 

"Good boy!" Harry crooned dazedly as he resumed his thrusts, now in a much less consuming position. "I won't be able to last much longer!" 

All in one moment Padfoot whined with affirmation, wiggled his butt a little, and quickly clenched his asshole 'round Harry's shaft, making the pubescent boy hiss with pleasure. "Ohhh shit! If you keep that up I'll cum even sooner!" 

Padfoot seemed to take that as a challenge. His hips pushed back while still wriggling so that Harry sank completely inside of him. Harry's breath caught hard in his chest as a positive wave of pleasure crashed over him. He gave a wail that, had he not been amid ecstasy, would have embarrassed him. But somehow he still held on, right at the edge of his orgasm. _I won't go down alone!_

Harry's arm slunk beneath Padfoot to wrap around his canine cock. The dog stiffened at the touch, momentarily ceasing its teasing movements. Harry grinned blearily through his pleasure and began stroking his Godfather off. 

He got results immediately in the form of long whimpers and revitalized squirming from the dog beneath him. Harry hardly had to thrust into Padfoot anymore. The work was being done for him! So the boy turned his full focus (or as much as could be spared through the intense pleasure) to servicing Padfoot. 

His red rocket was already as slick and sticky as could be, coated with a layer of pre over deep pink, membraneous flesh. It made stroking the dog off all the easier. His hand practically glided up and down the shaft, teasing at the knot on each upstroke. Padfoot's whines seemed to grow louder and louder with every move of Harry's hand. 

"Th-that's it!" Harry gasped out, stroking as quickly as he could in his exhausted state. "That's it, boy!"

But it wouldn't be enough to make Padfoot cum in time. Harry knew that if he came before the dog he wouldn't have enough energy left over to finish the job. It was likely sleep would claim him quickly after he completed his climax. Harry shifted his grip up to Padfoot's knot. He couldn't even get his hand fully around it, but he didn't need to. Not for what he wanted. 

"I'm gonna make you cum in m-my hand!" He squeezed the knot tentatively, testing boundaries. Padfoot froze up again, his whines now sounding frantic and needy. But he recovered quicker than before. Harry squeezed a little harder. This time Padfoot didn't stop, but the teen could feel the strain in his companion's movements, hear the need for release in his whines. It wouldn't be long, now. 

Harry went all in, giving it everything he had. His hips resumed thrusting, though they were slow, drained thrusts. He squeezed harder still on the knot and felt the fruits of his labor in the form of a pre-orgasm twitch of Padfoot's cock. He knew he could only keep this up for perhaps another minute, but it would be enough, to one end or the other. They were both unbelievably close. 

"Think about th-this, Padfoot," Harry murmured into the dog's ear, hoping he could push them both over the edge. "I'm b-barely fifteen. I'm your best mate's s-son! And I'm breeding you, fucking you in your d-dog form! Something no one else has d-d-done! I'm gonna make you cum all your doggy cum right in our bed, and th-then we're gonna sleep in it!"

It was more than enough. Padfoot bit down on the pillow he and Harry shared and howled into it. The pillow did practically nothing to muffle him. It was so loud that Harry was surprised it didn't wake the portrait downstairs. And then he realized he was howling too. The boy's vision filled with stars. He could feel his cock convulsing, spitting fiercely deep inside a canine anus. Padfoot's dick was mirroring Harry's, staining their sheets with dog spunk right over where he'd already dripped pre. 

Harry felt his voice give out. The room grew quieter, the only sounds now being Padfoot's whimpers and rustling fabric. Harry had arced his back as he came, so hard that the joints popped and muscles stretched, leaving him even more relaxed and tired as his orgasm faded away than usual. 

Harry didn't mean to pull out of Padfoot so quickly. But he couldn't help it. He was just too exhausted to function any longer. The teen fell down off of Padfoot's back and into the bedding on his side. One leg jutted out, knee bent to form a triangle. Despite being drained he felt a strange sense of fulfillment. A kind of completion. He'd been right, fucking something was what he needed. 

They didn't even bother to turn off the light. It would go out soon enough on its own, and the two men hadn't the will to do it themselves. Padfoot turned shakily around and curled up against Harry, resting his head atop the boy's protruding thigh. They could both feel the cum in the bedding beneath them, and knew more would be seeping out of Padfoot while they slept, but what could they do about it now, with sleep so near?

Harry wrapped an arm around Padfoot, snuggling him closely, and closed his eyes. He tried to wish Padfoot goodnight, but a full, dreamless sleep claimed him before he'd so much as properly gathered the words in head.

**Notes for the Chapter:**

> Comments make me cum

**Author's Note:**

> https://www.youtube.com/watch?v=BjfRlpIpFa0
> 
> I now have a tumblr where I post updates and answer questions and post random fandom stuff: https://www.tumblr.com/blog/dad-i-write-gay-porn


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